function SuperType(str) {
  this.str = str ?? "none";
  this.arr = [1, 2, 3];
  this.fn = () => console.log(1);
}
const superType = new SuperType("superType");
console.log(superType);

function SubType(num) {
  this.num = num;
  SuperType.call(this);
}
SubType.prototype = Object.create(SuperType.prototype);

/**
 * 优点：
 * 缺点：
 */

const subType = new SubType();
console.log("123\t,456");
